The real takeaway for the lay-folk is that there are questions which can be expressed in grammatically correct English which make no physical sense. We see that a lot here where people want to talk about specific electrons.

Does space-time beyond the known universe compute to zero since time does not exist (if nothing's happening . . . does time exist?). What are the implications for mass-energy equivalence in the absence of time? I would assume beyond the known universe if would be nice and quiet - no thermal noise out there.

Wouldn't it be more correct to say "physically meaningless on the current model or theory"? After all, the notion of individual electrons might actually be meaningful on the older, planetary or billiard ball model, but not on the current model. Similarly, the notion of an edge to the universe might actually have a meaning in an Aristotelian or Ptolemaic model of the universe, but again not in the current one. Of course to the best of our knowledge we should take the current model as truthful to some extent, but that doesn't mean it must serve as the basis for the meaning of all terms or sentences, including a physicalist sense. Doesn't it make better sense to think of meaning as being context dependent and what might be meaningless in one context could be meaningful in another?